期刊名称:Environmental Health - a Global Access Science Source
印刷版ISSN:1476-069X
电子版ISSN:1476-069X
出版年度:2008
卷号:7
期号:1
页码:48
DOI:10.1186/1476-069X-7-48
语种:English
出版社:BioMed Central
摘要:Several studies have shown cross-sectional associations between long term exposure to particulate air pollution and survival in general population or convenience cohorts. Less is known about susceptibility, or year to year changes in exposure. We investigated whether particles were associated with survival in a cohort of persons with COPD in 34 US cities, eliminating the usual cross-sectional exposure and treating PM10 as a within city time varying exposure. Using hospital discharge data, we constructed a cohort of persons discharged alive with chronic obstructive pulmonary disease using Medicare data between 1985 and 1999. 12-month averages of PM10 were merged to the individual annual follow up in each city. We applied Cox's proportional hazard regression model in each city, with adjustment for individual risk factors. We found significant associations in the survival analyses for single year and multiple lag exposures, with a hazard ratio for mortality for an increase of 10 μg/m3 PM10 over the previous 4 years of 1.22 (95% CI: 1.17–1.27). Persons discharged alive for COPD have substantial mortality risks associated with exposure to particles. The risk is evident for exposure in the previous year, and higher in a 4 year distributed lag model. These risks are significantly greater than seen in time series analyses.